This project seeks to improve outcomes in patients with emphysema. Therapies such as lung volume reduction surgery (LVRS) and lung transplantation (LTx) offer potential improvements in quality of life, but they impose substantial risks. Thus, decision making about the use of LVRS and LTx requires trade-offs. Rational analyses of these trade-offs require valid measurements of the benefits and harms to the patients in all relevant domains that effect duration and quality of life, including morbidity, functional status, symptoms, and satisfaction. We do not have an agreed upon standard of successful therapy, specifically in situations where duration of survival is not the only issue. The instruments we use to assess procedures may not fully capture the aspects of health and quality of life that are most important. New instruments and models for assessing outcomes are necessary to complement those that exist. The specific aims of this project are 1) to further develop methods to assess outcomes of patients with emphysema, and 2) to assess the effects of lung volume reduction surgery and lung transplant on outcomes of patients with emphysema. The effects of therapies on mortality and quality of life, measured as utilities, will be assessed. Patient demographics, co-morbidity, functional status, symptoms, and satisfaction, as well as intermediate physiologic outcomes, and utilization of resources will be measured. To achieve the specific aims, primary data collection will be performed in three ways: instrument validation, cross-sectional and (pre and post-operative) longitudinal studies. Models of the relationships among functional status, satisfaction, physiology, and quality of life in patients with emphysema will be developed and used to explain the relationships among the various outcomes. We will also develop operational definitions of successful and unsuccessful treatments among patients with emphysema undergoing LVRS or LTx that account for functional status, satisfaction, physiology, and quality of life, as well as mortality. Prediction rules for outcomes among patients with emphysema undergoing LVRS or LTx will be developed. This research plan promotes the development of methods for assessing and understanding the role of new technologies and therapeutic interventions in patients with emphysema.